JP2023167108A - Image forming method - Google Patents

Abstract

To provide an image formation method which is excellent in color development property, discharge stability and dryness on a non-permeable substrate.SOLUTION: An image forming method is provided, imparting treatment liquid, white ink and color ink onto a non-permeable substrate by one scan, wherein a head for ejecting the treatment liquid, a head for ejecting the white ink and a head for ejecting the color ink exist on the same carriage, the carriages is arranged parallel to a scan direction, the treatment liquid contains polyvalent metal salt, an organic solvent and a resin, the content of the polyvalent metal salt is 0.50 mass% or more and 2.0 mass% or less with respect to the total amount of the treatment liquid, the white ink contains coloring material, organic solvent and resin, the color ink contains coloring material, an organic solvent and resin, and viscosities at 25°C of the treatment liquid, the white ink and the color ink are 10 mPa or more and 12 mPa s or less.SELECTED DRAWING: None

Description

The present invention relates to an image forming method.

In recent years, in the commercial and industrial printing fields, where analog printing such as offset printing and flexo printing is the mainstream, there has been an increasing need for inkjet printers as digital printing capable of printing a wide variety of designs in small quantities without the need for plates. There is.
When producing a wide variety of printed matter in small quantities using digital printing, various types of printing substrates are used, but each printing substrate has different surface characteristics, and the quality of the printed matter depends on the characteristics. may affect.

In order to produce printed matter of the same quality on various substrates, it is known to apply a pretreatment liquid that increases ink receptivity before applying ink. In addition, the pretreatment liquid is required not only to improve the appearance of printed matter but also to improve the adhesion of images, and because the pretreatment liquid is to be discharged by an inkjet, ejectability is required.

For example, a treatment liquid composition has been proposed that uses a pretreatment liquid containing a cationic compound and other specific compounds to reduce ink penetration into a polyester base material and improve color development ( For example, see Patent Document 1).

An object of the present invention is to provide an image forming method that is excellent in color development, ejection stability, and drying property on a non-penetrating base material.

The present invention provides an image forming method in which a processing liquid, a white ink, and a color ink are applied to a non-permeable substrate in one scan, comprising: a head for discharging the processing liquid; and a head for discharging the white ink. and a head for ejecting the color ink are present on the same carriage, the carriage is arranged parallel to the scanning direction, and the processing liquid contains a polyvalent metal salt, an organic solvent, and a resin. and the content of the polyvalent metal salt is 0.50% by mass or more and 2.0% by mass or less based on the total amount of the processing liquid, and the white ink contains a coloring material, an organic solvent, and a resin. , the color ink contains a coloring material, an organic solvent, and a resin, and the viscosity of the treatment liquid, the white ink, and the color ink at 25° C. is 10 mPa·s or more and 12 mPa·s or less. shall be.

According to the present invention, it is possible to provide an image forming method that is excellent in color development, ejection stability, and drying property on a non-penetrating base material.

FIG. 1 is a perspective explanatory diagram showing an example of an image forming apparatus related to the present invention. FIG. 2 is a perspective explanatory view showing an example of a main tank in an image forming apparatus according to the present invention.

In the conventional technology as described in Patent Document 1, since the processing liquid and ink (white ink and color ink) have low viscosity, when ejecting with an inkjet method, the mist of the processing liquid or the ink is There has been a problem in that the mist is scattered and adjacent processing liquid or ink aggregates, resulting in nozzle clogging. In addition, attempts have been made to resolve nozzle clogging by adding a wetting agent (thickener) from the perspective of improving the viscosity of the processing liquid or ink, but it has been reported that drying properties (secondary drying properties) deteriorate. There were problems and room for further improvement.
In addition, in the conventional technology, by printing the treatment liquid, white ink, and color ink in multiple times, that is, by printing with the number of main scans (pass number) 2 or more, the base material / treatment liquid is printed in the order of lamination. When forming an image consisting of a layer/white ink layer/color ink layer, the aggregation effect of aggregation components such as polyvalent metal salts contained in the processing liquid may extend to the color ink layer on the white ink layer. First, there is a problem in that the color ink layer sinks.

As a result of extensive studies, the inventors of the present invention found that the content of the metal polyvalent salt contained in the processing liquid and the viscosity at 25°C were adjusted, and the processing liquid and the ink were printed in one scan. It was discovered that the composition has excellent coloring properties, ejection stability, and drying properties on non-permeable substrates.

By applying a treatment liquid to the substrate before applying white ink or color ink, bleeding and color unevenness caused by mixing of ink droplets can be improved, and the color ink layer on the white ink layer on the non-permeable substrate can be improved. can improve color development. This effect is derived from the polyvalent metal salt contained in the processing liquid. Compared to conventional materials such as cationic resins and organic acids, polyvalent metal salts have a low molecular weight and easy movement of cationic components, and they dissolve instantly in water, causing agglomeration of solid components. Since a cationic component is generated, when the ink is applied onto a substrate coated with the treatment liquid, the cationic component instantly moves throughout the layer, causing aggregation of the pigment. In addition, in the present invention, since the processing liquid and the ink are printed in one scan instead of being divided into multiple prints, the aggregation effect derived from the polyvalent metal salt extends to the color ink layer, causing the color ink layer to sink. can be suppressed.

Furthermore, by adding a resin to the treatment liquid and the ink to improve the viscosity, it is possible to suppress the energy required for drying and improve drying performance. In addition, the high viscosity of the processing liquid and ink can suppress the generation of mist during printing in one scan, and eliminate nozzle clogging caused by agglomeration of adjacent inks or processing liquids. can.

Therefore, the present invention provides an image forming method in which a processing liquid, a white ink, and a color ink are applied to a non-permeable substrate in one scan, comprising: a head for discharging the processing liquid; and a head for discharging the processing liquid; A head for ejecting the color ink and a head for ejecting the color ink exist on the same carriage, the carriage is arranged in parallel to the scanning direction, and the processing liquid contains polyvalent metal salts, organic solvents, and The white ink contains a resin, the content of the polyvalent metal salt is 0.50% by mass or more and 2.0% by mass or less based on the total amount of the processing liquid, and the white ink contains a coloring material, an organic solvent, and a resin. The color ink contains a coloring material, an organic solvent, and a resin, and the viscosity of the treatment liquid, the white ink, and the color ink at 25° C. is 10 mPa·s or more and 12 mPa·s or less. By doing so, it is possible to provide an image forming method that is excellent in color development, ejection stability, and drying property on a non-penetrating base material.

The present invention will be explained in detail below.

(Image forming method)
The image forming method of the present invention is an image forming method in which a processing liquid, a white ink, and a color ink are applied to a non-permeable substrate in one scan, and the method includes a head for discharging the processing liquid, a head for discharging the processing liquid, and the white ink. A head that ejects the color ink and a head that ejects the color ink are located on the same carriage, and the carriage is arranged parallel to the scanning direction. It may include a process.
Note that "one scan" in this specification indicates that the number of main scans of the carriage is one, or that the number of passes is one. Furthermore, in the case of a multi-pass printing method in which a carriage reciprocates on a recording medium to perform printing, the "single scan" does not refer to one reciprocating movement but to one-way movement in one direction.

<Ink>
In this specification, white ink and color ink may be collectively referred to as "ink."
The ink in the present invention contains an organic solvent, a coloring material, and a resin, and may contain other components as necessary.
Note that the white ink in the present invention refers to one in which a white coloring material is used as the coloring material, and the color ink in the present invention refers to ink in which a colored coloring material other than white is used as the coloring material.
The organic solvent, coloring material, resin, etc. used in the ink of the present invention will be explained below.

<<Organic solvent>>
The organic solvent contained in the ink is not particularly limited and can be appropriately selected depending on the purpose. For example, a water-soluble organic solvent can be used.
Examples of the water-soluble organic solvent include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, etc. can be mentioned. Specific examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol. , 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin , 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1 , 3-pentanediol, polyhydric alcohols such as petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether polyhydric alcohol alkyl ethers such as ethylene glycol monophenyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, Nitrogen-containing heterocyclic compounds such as 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone, formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethyl Amides such as propionamide, 3-butoxy-N,N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine, triethylamine, sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, thiodiethanol, propylene carbonate, ethylene carbonate, etc. can be mentioned.
As the organic solvent, it is preferable to use an organic solvent having a boiling point of 250° C. or lower because it not only functions as a wetting agent but also provides good drying properties.

As the organic solvent, polyol compounds having 8 or more carbon atoms and glycol ether compounds are also suitably used.
Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and the like.
Specific examples of the glycol ether compounds include polyhydric alcohols such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Alkyl ethers; examples include polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
The polyol compound having 8 or more carbon atoms and the glycol ether compound can improve the permeability of ink when paper is used as a recording medium.

The content of the organic solvent in the ink is not particularly limited and can be selected as appropriate depending on the purpose, but from the viewpoint of drying properties and ejection stability of the ink, it is preferably 10% by mass or more and 60% by mass or less. , more preferably 20% by mass or more and 60% by mass or less.

The organic solvent may be appropriately synthesized or a commercially available product.
Commercially available organic solvents include, for example, 1,2-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd., boiling point: 188°C), 3-methoxy-3-methyl-1-butanol (Kuraray Co., Ltd.) (manufactured by Tokyo Kasei Kogyo Co., Ltd., boiling point: 173°C), 2,3-butanediol (manufactured by Tokyo Kasei Kogyo Co., Ltd., boiling point: 182°C), and 2-ethylhexyl alcohol (manufactured by Tokyo Kasei Kogyo Co., Ltd., boiling point: 184°C).

＜＜Color material＞＞
The coloring material contained in the ink is not particularly limited, and pigments and dyes can be used.

-Pigment-
As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. Also, mixed crystals may be used.
Further, as the pigment, for example, a black pigment, a yellow pigment, a magenta pigment, a cyan pigment, a white pigment, a green pigment, an orange pigment, a glossy pigment such as gold or silver, a metallic pigment, etc. can be used.

The inorganic pigment is not particularly limited and can be appropriately selected depending on the purpose. For example, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, Carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used.
The organic pigment is not particularly limited and can be selected as appropriate depending on the purpose, such as azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments). , indigo pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc.), dye chelates (e.g., basic dye type chelates, acidic dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black, etc. . Among these pigments, those having good affinity with the solvent are preferably used. In addition, resin hollow particles and inorganic hollow particles can be used.

Specific examples of black pigments include carbon blacks (C.I. Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, or copper, iron (C.I. Pigment Black 11), Examples include metals such as titanium oxide and organic pigments such as aniline black (C.I. Pigment Black 1).
Specific examples of color pigments include C.I. I. Pigment Yellow 1, C. I. Pigment Yellow 3, C. I. Pigment Yellow 12, C. I. Pigment Yellow 13, C. I. Pigment Yellow 14, C. I. Pigment Yellow 17, C. I. Pigment Yellow 24, C. I. Pigment Yellow 34, C. I. Pigment Yellow 35, C. I. Pigment Yellow 37, C. I. Pigment Yellow 42 (yellow iron oxide), C.I. I. Pigment Yellow 53, C. I. Pigment Yellow 55, C. I. Pigment Yellow 74, C. I. Pigment Yellow 81, C. I. Pigment Yellow 83, C. I. Pigment Yellow 95, C. I. Pigment Yellow 97, C. I. Pigment Yellow 98, C. I. Pigment Yellow 100, C. I. Pigment Yellow 101, C. I. Pigment Yellow 104, C. I. Pigment Yellow 108, C. I. Pigment Yellow 109, C. I. Pigment Yellow 110, C. I. Pigment Yellow 117, C. I. Pigment Yellow 120, C. I. Pigment Yellow 138, C. I. Pigment Yellow 150, C. I. Pigment Yellow 153, C. I. Pigment Yellow 155, C. I. Pigment Yellow 180, C. I. Pigment Yellow 185, C. I. Pigment Yellow 213, C. I. Pigment Orange 5, C. I. Pigment Orange 13, C. I. Pigment Orange 16, C. I. Pigment Orange 17, C. I. Pigment Orange 36, C. I. Pigment Orange 43, C. I. Pigment Orange 51, C. I. Pigment Red 1, C. I. Pigment Red 2, C. I. Pigment Red 3, C. I. Pigment Red 5, C. I. Pigment Red 17, C. I. Pigment Red 22, C. I. Pigment Red 23, C. I. Pigment Red 31, C. I. Pigment Red 38, C. I. Pigment Red 48:2 (Permanent Red 2B (Ca)), C.I. I. Pigment Red 48:3, C.I. I. Pigment Red 48:4, C.I. I. Pigment Red 49:1, C.I. I. Pigment Red 52:2, C. I. Pigment Red 53:1, C.I. I. Pigment Red 57:1 (Brilliant Carmine 6B), C.I. I. Pigment Red 60:1, C.I. I. Pigment Red 63:1, C.I. I. Pigment Red 63:2, C.I. I. Pigment Red 64:1, C.I. I. Pigment Red 81, C. I. Pigment Red 83, C. I. Pigment Red 88, C. I. Pigment Red 101 (Red), C. I. Pigment Red 104, C. I. Pigment Red 105, C. I. Pigment Red 106, C. I. Pigment Red 108 (Cadmium Red), C.I. I. Pigment Red 112, C. I. Pigment Red 114, C. I. Pigment Red 122 (quinacridone magenta), C.I. I. Pigment Red 123, C. I. Pigment Red 146, C. I. Pigment Red 149, C. I. Pigment Red 166, C. I. Pigment Red 168, C. I. Pigment Red 170, C. I. Pigment Red 172, C. I. Pigment Red 177, C. I. Pigment Red 178, C. I. Pigment Red 179, C. I. Pigment Red 184, C. I. Pigment Red 185, C. I. Pigment Red 190, C. I. Pigment Red 193, C. I. Pigment Red 202, C. I. Pigment Red 207, C. I. Pigment Red 208, C. I. Pigment Red 209, C. I. Pigment Red 213, C. I. Pigment Red 219, C. I. Pigment Red 224, C. I. Pigment Red 254, C. I. Pigment Red 264, C. I. Pigment Violet 1 (Rhodamine Lake), C.I. I. Pigment Violet 3, C. I. Pigment Violet 5:1, C.I. I. Pigment Violet 16, C. I. Pigment Violet 19, C. I. Pigment Violet 23, C. I. Pigment Violet 38, C. I. Pigment Blue 1, C. I. Pigment Blue 2, C. I. Pigment Blue 15 (phthalocyanine blue), C.I. I. Pigment Blue 15:1, C. I. Pigment Blue 15:2, C. I. Pigment Blue 15:3, C. I. Pigment Blue 15:4 (phthalocyanine blue), C.I. I. Pigment Blue 16, C. I. Pigment Blue 17:1, C. I. Pigment Blue 56, C. I. Pigment Blue 60, C. I. Pigment Blue 63, C. I. Pigment Green 1, C. I. Pigment Green 4, C. I. Pigment Green 7, C. I. Pigment Green 8, C. I. Pigment Green 10, C. I. Pigment Green 17, C. I. Pigment Green 18, C. I. Pigment Green 36 and the like.

-dye-
The dye is not particularly limited and can be appropriately selected depending on the purpose, and acid dyes, direct dyes, reactive dyes, and basic dyes can be used. These may be used alone or in combination of two or more.
Specific examples of the dye include C.I. I. Acid Yellow 17, C. I. Acid Yellow 23, C. I. Acid Yellow 42, C. I. Acid Yellow 44, C. I. Acid Yellow 79, C. I. Acid Yellow 142, C. I. Acid Red 52, C. I. Acid Red 80, C. I. Acid Red 82, C. I. Acid Red 249, C. I. Acid Red 254, C. I. Acid Red 289, C. I. Acid Blue 9, C. I. Acid Blue 45, C. I. Acid Blue 249, C. I. Acid Black 1, C. I. Acid Black 2, C. I. Acid Black 24, C. I. Acid Black 94, C. I. Food black 1, C. I. Food Black 2, C. I. Direct Yellow 1, C. I. Direct Yellow 12, C. I. Direct Yellow 24, C. I. Direct Yellow 33, C. I. Direct Yellow 50, C. I. Direct Yellow 55, C. I. Direct Yellow 58, C. I. Direct Yellow 86, C. I. Direct Yellow 132, C. I. Direct Yellow 142, C. I. Direct Yellow 144, C. I. Direct Yellow 173, C. I. Direct Red 1, C. I. Direct Red 4, C. I. Direct Red 9, C. I. Direct Red 80, C. I. Direct Red 81, C. I. Direct Red 225, C. I. Direct Red 227, C. I. Direct Blue 1, C. I. Direct Blue 2, C. I. Direct Blue 15, C. I. Direct Blue 71, C. I. Direct Blue 86, C. I. Direct Blue 87, C. I. Direct Blue 98, C. I. Direct Blue 165, C. I. Direct Blue 199, C. I. Direct Blue 202, C. I. Direct Black 19, C. I. Direct Black 38, C. I. Direct Black 51, C. I. Direct Black 71, C. I. Direct Black 154, C. I. Direct Black 168, C. I. Direct Black 171, C. I. Direct Black 195, C. I. Reactive Red 14, C. I. Reactive Red 32, C. I. Reactive Red 55, C. I. Reactive Red 79, C. I. Reactive Red 249, C. I. Reactive Black 3, C. I. Reactive Black 4, C. I. Examples include Reactive Black 35.

The content of the coloring material in the ink is preferably 0.1% by mass or more and 15% by mass or less, and 1% by mass or more and 10% by mass or less from the viewpoint of improving image density, good fixing properties, and ejection stability. More preferred.

Methods for obtaining ink by dispersing pigments include, for example, introducing hydrophilic functional groups into the pigment to make it a self-dispersing pigment, coating the surface of the pigment with a resin and dispersing it, and using a dispersant. Examples include a method of dispersion.
An example of a method of introducing a hydrophilic functional group into a pigment to make it a self-dispersing pigment is to add a functional group such as a sulfone group or a carboxyl group to a pigment (for example, carbon) to make it dispersible in water. can be mentioned.
Examples of methods for coating the surface of pigments with resin and dispersing them include a method in which the pigments are encapsulated in microcapsules and made dispersible in water. This can be referred to as a resin-coated pigment. In this case, all the pigments blended into the ink do not need to be coated with the resin, and uncoated pigments or partially coated pigments may be dispersed in the ink as long as the effects of the present invention are not impaired. You can leave it there.
Examples of the method for dispersing using a dispersant include methods for dispersing using known low-molecular-type dispersants and polymer-type dispersants, typified by surfactants. The dispersant can be appropriately selected depending on the pigment, and for example, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. can be used. RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and a formalin condensate of naphthalene sulfonate can also be suitably used as the dispersant. These may be used alone or in combination of two or more.

-Pigment dispersion-
It is possible to obtain an ink by mixing materials such as water and an organic solvent with the pigment. It is also possible to produce ink by mixing a pigment, water, a dispersant, etc. to form a pigment dispersion, and then mixing materials such as water and an organic solvent.
The pigment dispersion is obtained by mixing and dispersing water, a pigment, a pigment dispersant, and other components as necessary, and adjusting the particle size. A disperser may be used for the dispersion.

There is no particular restriction on the particle size of the pigment in the pigment dispersion, but the maximum frequency in terms of the maximum number of particles is desirable because the dispersion stability of the pigment is good and the image quality such as ejection stability and image density is also high. The thickness is preferably 20 nm or more and 500 nm or less, more preferably 20 nm or more and 150 nm or less.
The particle size of the pigment in the pigment dispersion can be measured using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

The pigment content in the pigment dispersion is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of obtaining good ejection stability and increasing image density, 0.1 It is preferably from 0.1% by mass to 30% by mass, more preferably from 0.1% by mass to 30% by mass.

It is preferable that the pigment dispersion is filtered to remove coarse particles using a filter, a centrifugal separator, etc., and then degassed, if necessary.

<<Resin>>
The resin contained in the ink is not particularly limited and can be appropriately selected depending on the purpose, such as urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, Examples include styrene-butadiene resin, vinyl chloride resin, acrylic styrene resin, and acrylic silicone resin. Resin particles made of these resins may also be used. It is possible to obtain an ink by mixing the resin particles with materials such as colorants and organic solvents in the state of a resin emulsion in which water is used as a dispersion medium. These may be used alone or in combination of two or more types of resin particles.

The volume average particle diameter of the resin particles is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of obtaining good fixing properties and high image hardness, it is preferably 10 nm or more and 1,000 nm or less. , more preferably 10 nm or more and 200 nm or less, and even more preferably 10 nm or more and 100 nm or less.
The volume average particle diameter can be measured, for example, using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

The content of the resin is not particularly limited and can be selected as appropriate depending on the purpose, but from the viewpoint of fixing properties and storage stability of the ink, it is 1% by mass or more and 30% by mass based on the total amount of ink. The following is preferable, and 5% by mass or more and 20% by mass or less is more preferable.

There is no particular restriction on the particle size of the solid content in the ink, and it can be selected as appropriate depending on the purpose, but from the viewpoint of improving ejection stability and image quality such as image density, The maximum frequency is preferably 20 nm or more and 1000 nm or less, more preferably 20 nm or more and 150 nm or less. Note that the solid content includes resin particles, pigment particles, and the like.
The particle size of the solid content in the ink can be measured using a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

The resin particles may be appropriately synthesized or commercially available.

<<Other ingredients>>
The other components are not particularly limited and can be selected as appropriate depending on the purpose. Examples include.

<<<Surfactant>>>
As the surfactant contained in the ink, any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants, and anionic surfactants can be used. These may be used alone or in combination of two or more.

-Silicone surfactant-
The silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose, but one that does not decompose even at high pH (pH 11 to 14) is preferred.
Examples of silicone surfactants that do not decompose even at high pH (pH 11 to 14) include side chain-modified polydimethylsiloxane, double-end modified polydimethylsiloxane, single-end modified polydimethylsiloxane, and both side-chain-modified polydimethylsiloxanes. can be mentioned. Among these, those having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modified group are preferred from the viewpoint of improving hydrophilicity and increasing solubility in water.
Moreover, a polyether-modified silicone surfactant can also be used as the silicone surfactant.

The polyether-modified silicone surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples include those introduced into the side chain of the Si part of siloxane.
...General formula (S-1)
(However, in the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R' represents an alkyl group.)

As the silicone surfactant, a suitably synthesized one may be used, or a commercially available product may be used.
Commercially available silicone surfactants are available from, for example, BIC Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Dow Corning Toray Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd., and the like.
Commercially available polyether-modified silicone surfactants include, for example, KF-618, KF-642, KF-643 (all manufactured by Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-1906EX ( All are manufactured by Nippon Emulsion Co., Ltd.), DOWSIL (registered trademark) FZ-2105, DOWSIL (registered trademark) FZ-2118, DOWSIL (registered trademark) FZ-2154, DOWSIL (registered trademark) FZ-2161, DOWSIL (registered trademark) ) FZ-2162, DOWSIL (registered trademark) FZ-2163, DOWSIL (registered trademark) FZ-2164 (all manufactured by Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (all manufactured by BYK Chemie Co., Ltd.) (manufactured by Momentive Performance Materials Japan), TSF4440, TSF4452, and TSF4453 (all manufactured by Momentive Performance Materials Japan).

-Fluorine surfactant-
The fluorine-based surfactant is not particularly limited and can be selected as appropriate depending on the purpose, but compounds with 2 to 16 fluorine-substituted carbons are preferred, and compounds with 4 to 16 fluorine-substituted carbons are preferred. 16 is more preferred.
Examples of the fluorine-based surfactants include perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and perfluoroalkyl ether groups in the side chains. Examples include polyoxyalkylene ether polymer compounds having
Examples of the perfluoroalkylsulfonic acid compound include perfluoroalkylsulfonic acid, perfluoroalkylsulfonic acid salts, and the like.
Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acids and perfluoroalkylcarboxylic acid salts.
The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in its side chain includes a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in its side chain, and a sulfate salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in its side chain. Examples include salts of polyoxyalkylene ether polymers.

Among these, polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain are preferred from the viewpoint of low foaming properties, and fluorine ether polymer compounds represented by general formulas (F-1) and (F-2) are preferred. type surfactants are more preferred.

...General formula (F-1)
In the compound represented by the above general formula (F-1), from the viewpoint of imparting water solubility, m is preferably an integer of 0 to 10, and n is preferably an integer of 0 to 40.

C _n F _2n+1 -CH ₂ CH(OH)CH ₂ -O-(CH ₂ CH ₂ O) _a -Y
...General formula (F-2)
In the compound represented by the above general formula (F-2), Y is H, or CmF _2m+1 (m is an integer of 1 to 6), or CH ₂ CH(OH)CH ₂ -CmF _2m+1 (m is 4 to 6 ), or CpH _2p+1 (p is an integer from 1 to 19). n is an integer from 1 to 6. a is an integer from 4 to 14.

Counter ions of the salts in these fluorosurfactants include Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) Examples include ₃ .

As the fluorosurfactant, a suitably synthesized one may be used, or a commercially available product may be used.
Examples of commercially available fluorosurfactants include Surflon S-111, Surflon S-112, Surflon S-113, Surflon S-121, Surflon S-131, Surflon S-132, Surflon S-141, Surflon S-145 (all manufactured by AGC Corporation); Fullard FC-93, Fullard FC-95, Fullard FC-98, Fullard FC-129, Fullard FC-135, Fullard FC-170C, Fullard FC-430, Fullard FC -431 (all manufactured by 3M Japan Ltd.); Megafac F-470, Megafac F-1405, Megafac F-474 (all manufactured by DIC Corporation); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, Capstone FS-31, Capstone FS-3100, Capstone FS-34, Capstone FS-35 (all , manufactured by Chemours); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, Polyfox PF- 156A, Polyfox PF-151N, Polyfox PF-154, Polyfox PF-159 (all manufactured by Omnova), and Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.). Among these, FS-3100, FS-34, FS-300 manufactured by Chemours Co., Ltd., and FS-300 manufactured by Chemours, Ltd. FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos, Polyfox PF-151N manufactured by Omnova, and Unidyne DSN-403N manufactured by Daikin Industries, Ltd. preferable.

- Amphoteric surfactant -
The amphoteric surfactant is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, and the like.

-Nonionic surfactant-
The nonionic surfactant is not particularly limited and can be appropriately selected depending on the purpose, such as polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkyl Examples include amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and ethylene oxide adduct of acetylene alcohol.

-Anionic surfactant-
The anionic surfactant is not particularly limited and can be appropriately selected depending on the purpose, for example, polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether. Examples include sulfate salts.

The content of the surfactant contained in the ink is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of excellent wettability and ejection stability and improved image quality, it is 0.001 It is preferably from 0.05% by mass to 5% by mass, more preferably from 0.05% by mass to 5% by mass.

<<<Defoaming agent>>>
The surfactant used as the other component can also be used as an antifoaming agent.
The antifoaming agent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include silicone antifoaming agents, polyether antifoaming agents, fatty acid ester antifoaming agents, and the like. These may be used alone or in combination of two or more. Among these, silicone antifoaming agents are preferred because they have excellent foam-breaking effects.

＜＜＜Preservative and fungicidal agent＞＞＞
The preservative and fungicide is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, 1,2-benzisothiazolin-3-one.

<<<Rust preventive agent>>>
The rust preventive agent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include acidic sulfites, sodium thiosulfate, and the like.

<<<pH adjuster>>>
The pH adjuster is not particularly limited as long as it can adjust the pH to 7 or more, and can be appropriately selected depending on the purpose, and examples thereof include amines such as diethanolamine and triethanolamine.

<<<Antibacterial agent>>>
The antibacterial agent is not particularly limited and can be appropriately selected depending on the purpose, such as 1,2-benzothiazolin-3-one. Examples of commercially available antibacterial agents include the trade name Proxel LV (manufactured by Arch Chemicals Japan).

＜＜＜Water＞＞＞
The water is not particularly limited and can be appropriately selected depending on the purpose.
The water content in the ink is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of ink drying properties and ejection reliability, it is preferably 10% by mass or more and 90% by mass or less, and 20% by mass or less. More preferably 60% by mass or less.

The viscosity of the ink in the present invention at 25° C. is 10 mPa·s or more and 12 mPa·s or less. When the viscosity of the ink at 25° C. is within the above range, the energy required for drying can be suppressed and drying performance can be improved, and the generation of mist when printing in one scan can be suppressed. Nozzle clogging caused by aggregation of adjacent ink compositions can be eliminated.
As a method for measuring the viscosity of the ink in the present invention, for example, a rotational viscometer (RE-80L, manufactured by Toki Sangyo Co., Ltd.) can be used. The measurement conditions are 25° C., a standard cone rotor (1°34′×R24), sample liquid volume of 1.2 mL, rotation speed of 50 rpm, and 3 minutes.

The physical properties of the ink are not particularly limited and can be appropriately selected depending on the purpose. For example, it is preferable that the surface tension, pH, etc. are within the following ranges.
The surface tension of the ink at 25° C. is preferably 35 mN/m or less, more preferably 32 mN/m or less, from the standpoint of suitably leveling the ink on the recording medium and shortening the drying time of the ink.
The pH of the ink is preferably 7 to 12, more preferably 8 to 11, from the viewpoint of preventing corrosion of metal members in contact with the ink.

The method for producing the ink is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be obtained by mixing and stirring the above-mentioned ink materials.

<Processing liquid>
The treatment liquid contains a polyvalent metal salt, an organic solvent, and a resin, and may contain other components as necessary.

<<Polyvalent metal salt>>
The polyvalent metal salt rapidly aggregates the coloring material in the ink, suppresses color bleeding, and improves color development. The polyvalent metal salt is preferably a divalent metal salt or a trivalent metal salt from the viewpoint of improving color development.
The divalent metal salt is not particularly limited and can be appropriately selected depending on the purpose. Examples include calcium carbonate, calcium nitrate, calcium chloride, calcium acetate, calcium sulfate, magnesium chloride, magnesium acetate, magnesium sulfate, etc. Can be mentioned.
The trivalent metal salt is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include aluminum sulfate, aluminum silicate, aluminum lactate, and the like.

The content of the polyvalent metal salt in the present invention is 0.50% by mass or more and 2.0% by mass or less based on the total amount of the treatment liquid.
When the content of the polyvalent metal salt is 0.50% by mass or more based on the total amount of the treatment liquid, color development can be improved.
When the content of the polyvalent metal salt is 2.0% by mass or less based on the total amount of the treatment liquid, discharge stability can be improved.

The polyvalent metal salt may be appropriately synthesized or a commercially available product.
Commercially available products of the polyvalent metal salt include, for example, the trade names of calcium acetate monohydrate (substance name: calcium acetate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., valence: divalent), magnesium acetate tetrahydrate. aluminum silicate (substance name: aluminum silicate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., valence: trivalent) , potassium acetate (substance name: potassium acetate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., valence: monovalent).

<<Organic solvent>>
The organic solvent contained in the treatment liquid is not particularly limited and can be appropriately selected depending on the purpose, and the same solvents as those described in the <<Organic solvent>> section of <Ink> above are used. can do.
Note that the organic solvent contained in the treatment liquid does not have a boiling point of 200° C. or higher.

<<Resin>>
The resin contained in the treatment liquid is not particularly limited and can be appropriately selected depending on the purpose, such as urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin. , styrene-butadiene resin, vinyl chloride resin, acrylic styrene resin, acrylic silicone resin, etc. Resin particles made of these resins may also be used. It is possible to obtain a treatment liquid by mixing the resin particles in the state of a resin emulsion in which water is used as a dispersion medium with a material such as a polyvalent metal salt or an organic solvent.

The glass transition temperature (Tg) of the resin contained in the treatment liquid is preferably 0°C or higher, more preferably 30°C or higher.
It is preferable that the glass transition temperature (Tg) of the resin contained in the treatment liquid is within the above numerical range because drying properties are improved.
Note that the glass transition temperature (Tg) can be measured using a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation).

The content of the resin contained in the treatment liquid is preferably 4.0% by mass or more and 15.0% by mass or less, and 5.0% by mass or more and 10.0% by mass or less based on the total amount of the treatment liquid. is more preferable.
It is preferable that the content of the resin contained in the treatment liquid is within the above numerical range because the discharge stability and drying properties will be good.

The volume average particle diameter of the resin contained in the processing liquid is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of obtaining good fixing properties and high image hardness, it is 10 nm or more. 000 nm or less, more preferably 10 nm or more and 200 nm or less, even more preferably 10 nm or more and 100 nm or less.
The volume average particle diameter of the resin contained in the treatment liquid can be measured using, for example, a particle size analyzer (Nanotrac Wave-UT151, manufactured by Microtrac Bell Co., Ltd.).

As the resin contained in the treatment liquid, a suitably synthesized resin may be used, or a commercially available resin may be used. Examples of commercially available products include UW-550CS (manufactured by Taisei Fine Chemical Co., Ltd., Tg: 50/40), Hydran WLI-611 (manufactured by DIC Corporation, Tg: -15°C), and Superflex E2000 (manufactured by DIC Corporation, Tg: -15°C). Daiichi Kogyo Seiyaku Co., Ltd., Tg: -38℃), Superflex 500M (Daiichi Kogyo Seiyaku Co., Ltd., Tg: -39℃), Vinibran 1008 (Nissin Chemical Co., Ltd., Tg: 30℃) , Vinibran 1225 (manufactured by Nissin Chemical Industry Co., Ltd., Tg: 9°C), Viniblan GV-6181 (manufactured by Nissin Chemical Industry Co., Ltd., Tg: 30°C), Viniblan 1017-AD (manufactured by Nissin Chemical Industry Co., Ltd., Tg: 31°C), Vinybran 1245L (manufactured by Nissin Chemical Industry Co., Ltd., Tg: -13°C), and the like.

<<Other ingredients>>
Other components in the treatment liquid are not particularly limited and can be selected as appropriate depending on the purpose, for example, the same components as those described in the section of <<Other components>> in <Ink> above. can be used.

The method for producing the treatment liquid is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be obtained by mixing and stirring the above-mentioned treatment liquid materials.

<Non-permeable base material>
The impermeable base material in the present invention is a base material that has a surface with low water permeability and low absorbency, and also includes materials that have many cavities inside but are not open to the outside. refers to a base material that has a water absorption amount of 10 mL/m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method. In addition, in this specification, the said non-permeable base material may be called a "recording medium."

The impermeable base material is not particularly limited and can be appropriately selected depending on the purpose; for example, vinyl chloride resin film, polyethylene terephthalate (PET) film, polypropylene, polyethylene, polycarbonate film, nylon film, etc. It can be suitably used.
Commercially available polypropylene films include, for example, P-2002, P-2161, P-4166 (all manufactured by Toyobo Co., Ltd.), PA-20, PA-30, PA-20W (all manufactured by Suntox (manufactured by Futamura Chemical Co., Ltd.), FOA, FOS, FOR (all manufactured by Futamura Chemical Co., Ltd.).
Specific examples of the polyethylene terephthalate film include trade names such as E-5100 (manufactured by Toyobo Co., Ltd.), E-5102 (manufactured by Toyobo Co., Ltd.), P60 (manufactured by Toray Industries, Inc.), P375 (manufactured by Toray Industries, Inc.), Examples include G2 (manufactured by Toyobo Co., Ltd.), G2P2 (manufactured by Toyobo Co., Ltd.), K (manufactured by Toyobo Co., Ltd.), and SL (manufactured by Toyobo Co., Ltd.).
Examples of the nylon film include Harden Film N-1100 (manufactured by Toyobo Co., Ltd.), N-1102 (manufactured by Toyobo Co., Ltd.), N-1200 (manufactured by Toyobo Co., Ltd.), ON (manufactured by Unitika Co., Ltd.), and NX (manufactured by Unitika Co., Ltd.). (manufactured by Unitika Co., Ltd.), MS (manufactured by Unitika Co., Ltd.), and NK (manufactured by Unitika Co., Ltd.).

<Image forming apparatus and image forming method>
The image forming method of the present invention is an image forming method in which a processing liquid, a white ink, and a color ink are applied to a non-permeable substrate in one scan, and the method includes a head for discharging the processing liquid, a head for discharging the processing liquid, and the white ink. A head for ejecting color ink and a head for ejecting the color ink are located on the same carriage, and the carriage is arranged parallel to the scanning direction.
The image forming apparatus according to the present invention is not particularly limited as long as it is capable of ejecting ink, various processing liquids, etc. onto a recording medium, and can be appropriately selected depending on the purpose. A applying means for applying a treatment liquid, a white ink, and a color ink to a non-permeable substrate in one scan, a head for discharging the treatment liquid, a head for discharging the white ink, and a head for discharging the color ink. Preferably, the apparatus includes a carriage having a head. Moreover, it is preferable that the carriage is arranged parallel to the scanning direction.
The image forming method can be preferably carried out by the image forming apparatus.

The ink of the present invention can be suitably used in various image forming apparatuses using an inkjet recording method, such as printers, facsimile machines, copying machines, printer/fax/copier multifunction machines, three-dimensional modeling apparatuses, and the like.

The image forming apparatus can include not only a head portion for ejecting ink, but also means for feeding, transporting, and discharging a recording medium, devices called a pre-processing device, a post-processing device, and the like.

As one aspect of the pre-processing device and the post-processing device, as in the case of ink such as black (K), cyan (C), magenta (M), yellow (Y), a pre-processing liquid and a post-processing liquid are used. There is a mode in which a liquid storage section and a liquid ejection head are added, and a pre-processing liquid and a post-processing liquid are ejected using an inkjet recording method.
Another aspect of the pre-processing device and the post-processing device is a mode in which a pre-processing device and a post-processing device using a device other than an inkjet recording method, such as a blade coating method, a roll coating method, or a spray coating method, are provided. .

The image forming apparatus may include heating means and drying means.
The image forming method may include a heating step and a drying step as other steps.
The heating step can be performed by the heating means, and the drying step can be performed by the drying means.
The heating means and the drying means include, for example, means for heating and drying the printed surface and back surface of the recording medium. The heating means and the drying means are not particularly limited, but for example, a hot air heater or an infrared heater can be used. Note that heating and drying can be performed before, during, or after printing.

The image forming apparatus and the image forming method are not limited to those in which significant images such as characters and figures are visualized using ink. For example, it includes those that form patterns such as geometric patterns, and those that form three-dimensional images.
Further, the image forming apparatus includes both a serial type apparatus in which an ejection head is moved and a line type apparatus in which an ejection head is not moved, unless specifically limited. Furthermore, the image forming apparatus may include not only a desktop type but also a wide recording device capable of printing on an A0 size recording medium, and, for example, a continuous paper wound into a roll may be used as the recording medium. It also includes a continuous feed printer that can be used.

The method of using the treatment liquid and ink in the present invention is not particularly limited and can be appropriately selected depending on the purpose. , bar coating method, roll coating method, knife coating method, air knife coating method, comma coating method, U comma coating method, AKKU coating method, smoothing coating method, microgravure coating method, reverse roll coating method, four roll coating method, It can be used in five roll coating methods, dip coating methods, curtain coating methods, slide coating methods, die coating methods, etc.

The use of the ink of the present invention is not particularly limited and can be appropriately selected depending on the purpose. For example, it can be applied to printed matter, paint, coating material, base material, etc. Furthermore, it can be used not only as an ink to form two-dimensional characters and images, but also as a three-dimensional modeling material for forming three-dimensional three-dimensional images (three-dimensional objects).
A known three-dimensional modeling device for modeling a three-dimensional object can be used, and is not particularly limited, but for example, one equipped with an ink storage means, a supply means, an ejection means, a drying means, etc. is used. be able to. The three-dimensional molded object includes a three-dimensional molded object obtained by, for example, applying multiple coats of ink. It also includes molded products obtained by processing a structure in which ink is applied onto a base material such as a recording medium. The molded product is, for example, a recorded matter or structure formed in the form of a sheet or film, subjected to molding processing such as heating stretching or punching. - Suitable for use in applications where the surface is decorated and then molded, such as meters and operation panels for electronic devices and cameras.

In the terms of the present invention, image formation, recording, printing, printing, etc. are all synonymous.
Recording medium, media, and printing material are all synonyms.
Unless otherwise specified, ink preparation and evaluation were performed at 25° C. and 60% humidity.

Here, one aspect of an image forming apparatus according to an embodiment will be described with reference to FIGS. 1 and 2. However, the application of the present invention is not limited to these embodiments in any way.
In addition, in each drawing, the same components are given the same reference numerals, and duplicate explanations may be omitted. Further, the number, position, shape, etc. of the following constituent members are not limited to this embodiment, and can be set to a preferable number, position, shape, etc. for implementing the present invention.

FIG. 1 is a perspective explanatory diagram showing an example of an image forming apparatus related to the present invention. FIG. 2 is a perspective explanatory view showing an example of a main tank in an image forming apparatus according to the present invention.
Image forming apparatus 400, which is an example of an image forming apparatus, is a serial type image forming apparatus. A mechanism section 420 is provided within the exterior 401 of the image forming apparatus 400. Each ink storage section 411 of the ink storage containers (also referred to as ink cartridges) 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is as follows: For example, it is formed from a packaging member such as an aluminum laminate film. The ink storage section 411 is housed in a container case 414 made of plastic, for example. The ink storage portion 411 stores ink liquid L. On the other hand, a cartridge holder 404 is provided on the back side of the opening when the cover 401c of the apparatus main body is opened. A main tank 410 is detachably attached to the cartridge holder 404. As a result, each ink discharge port 413 of the main tank 410 and the ejection head 434 for each color communicate with each other via the supply tube 436 for each color, and ink can be ejected from the ejection head 434 onto the recording medium.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In addition, "parts" in the examples are "parts by mass", and "%" is "% by mass" except for those in the evaluation criteria.

(Ink production example 1)
<Preparation of cyan pigment dispersion>
A cyan pigment dispersion was obtained in the same manner as the method described in -Method A- of [Pigment surface modification treatment] in JP-A-2012-207202.
Specifically, C. I. Pigment Blue 15:3 (trade name: Chromofine Blue, manufactured by Dainichiseika Chemical Industry Co., Ltd.) 20 g, 20 mmol of the compound of the following structural formula (1), and 200 mL of ion-exchanged water were mixed using a Silverson mixer (manufactured by Silverson). , and mixed at 6,000 rpm in a room temperature environment to obtain a slurry. When the pH of the obtained slurry was higher than 4, 20 mmol of nitric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was added. After stirring for 30 minutes, sodium nitrite (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (20 mmol) dissolved in a small amount of ion-exchanged water was slowly added to the slurry. Furthermore, by heating to 60° C. with stirring and reacting for 1 hour, the C. I. A modified pigment was obtained by adding a compound of the following structural formula (1) to the surface of Pigment Blue 15:3. Next, the pH was adjusted to 10 using an aqueous NaOH solution (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.), and after stirring for 30 minutes, a modified pigment dispersion was obtained. Ultrafiltration using a dialysis membrane was performed using the modified pigment dispersion and ion-exchanged water, and further ultrasonic dispersion was performed to obtain a bisphosphonic acid group as a hydrophilic functional group with a pigment concentration of 15% by mass. A cyan pigment dispersion (self-dispersion type) was obtained.
...Structural formula (1)

(Ink production example 2)
<Preparation of magenta pigment dispersion>
In the above <Preparation of cyan pigment dispersion>, "C.I. Pigment Blue 15:3 20g" was changed to "C.I. Pigment Red 122 (product name: Toner Magenta EO02, manufactured by Clariant Japan Co., Ltd.) 20g" Except for the above, a magenta pigment dispersion having a pigment concentration of 15% by mass was produced in the same manner as the production of the cyan pigment dispersion.

(Ink production example 3)
<Preparation of yellow pigment dispersion>
In the above <Preparation of cyan pigment dispersion>, 20 g of "C.I. Pigment Blue 15:3" was replaced with 20 g of "C.I. Pigment Yellow 74 (trade name: First Yellow 531, manufactured by Dainichiseika Kagyo Co., Ltd.)" A yellow pigment dispersion having a pigment concentration of 15% by mass was produced in the same manner as the production of the cyan pigment dispersion, except that the pigment concentration was changed to .

(Ink production example 4)
<Preparation of black pigment dispersion>
The above <Preparation of cyan pigment dispersion> is the same as the preparation of cyan pigment dispersion except that "C.I. Pigment Blue 15:3 20g" is changed to "Carbon black (NIPEX160, manufactured by degussa) 20g". A black pigment dispersion having a pigment concentration of 15% by mass was prepared.

(Ink production example 5)
<Preparation of white pigment dispersion>
25 g of titanium oxide (product name: STR-100W, manufactured by Sakai Chemical Industry Co., Ltd.), 5 g of a pigment dispersant (product name: TEGO Dispers 651, manufactured by Evonik), and 70 g of water were mixed, and mixed in a bead mill (product name: Research Lab, Inc.). A white pigment dispersion with a volume average particle diameter of 285 nm was prepared by dispersing 0.3 mm Φ zirconia beads at a filling rate of 60% and a speed of 8 m/s for 5 minutes.

(Production example 1 of resin particles)
<Preparation of polycarbonate urethane resin particle liquid>
Polycarbonate diol (a reaction product of 1,6-hexanediol and dimethyl carbonate, manufactured by Asahi Kasei Chemicals Co., Ltd., number average molecular weight (Mn): 1,200) was placed in a reaction vessel equipped with a stirrer, a reflux condenser, and a thermometer. ) 1,500 g, 220 g of 2,2-dimethylolpropionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) (hereinafter sometimes referred to as "DMPA"), and N-methylpyrrolidone (manufactured by Mitsubishi Chemical Corporation) (hereinafter referred to as 1,347 g (sometimes referred to as "NMP") was charged under a nitrogen stream and heated to 60° C. to dissolve DMPA.
Next, 1,445 g of 4,4'-dicyclohexylmethane diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2.6 g of dibutyltin dilaurylate (catalyst) (manufactured by Tokyo Chemical Industry Co., Ltd.) were added and heated to 90 ° C. The urethane reaction was carried out over 5 hours to obtain an isocyanate-terminated urethane prepolymer. This reaction mixture was cooled to 80°C, 149 g of triethylamine (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was added, 4,340 g was extracted from the mixture, and under strong stirring, 5,400 g of water and triethylamine were added. It was added to 15 g of the mixed solution.
Next, 1,500 g of ice was added, and 626 g of a 35% by mass 2-methyl-1,5-pentanediamine aqueous solution (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to carry out a chain extension reaction, resulting in a solid concentration of 40% by mass. The solvent was distilled off to obtain a polycarbonate urethane resin particle liquid 1.
Regarding the obtained polycarbonate-based urethane resin particle liquid 1, the glass transition point (hereinafter also referred to as "Tg") of the resin was measured, and the Tg was -20°C. Note that the Tg was measured using a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation).

(Production example 2 of resin particles)
<Preparation of polyester urethane resin particle liquid>
In a nitrogen-substituted container equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, polyester polyol ("Polylite OD-X-2251", manufactured by DIC Corporation, weight average molecular weight: 2,000) 100.2 parts by mass, 15.7 parts by mass of 2,2-dimethylolpropionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 48.0 parts by mass of isophorone diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.), and methyl ethyl ketone (manufactured by Sankyo Chemical Co., Ltd.) as an organic solvent. 77.1 parts by mass (manufactured by Tokyo Chemical Industry Co., Ltd.) were reacted using 0.06 parts by mass of dibutyltin dilaurate (hereinafter sometimes referred to as "DMTDL") (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst. After continuing the reaction for 4 hours, 30.7 parts by mass of methyl ethyl ketone was supplied as a diluting solvent, and the reaction was further continued. When the weight average molecular weight of the reactant reaches a range of 20,000 to 60,000, 1.4 parts by mass of methanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) is added to terminate the reaction. , an organic solvent solution of urethane resin was obtained. By adding 13.4 parts by mass of a 48% by mass potassium hydroxide aqueous solution (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) to the organic solvent solution of the urethane resin, the carboxyl groups possessed by the urethane resin were neutralized. Next, 715.3 parts by mass of water was added and thoroughly stirred, followed by aging and solvent removal to obtain a polyester-based urethane resin particle liquid 2 having a solid content concentration of 30% by mass.
Regarding the obtained polyester-based urethane resin particle liquid 2, the Tg measured in the same manner as described above (Production Example 1 of Resin Particles) was 57°C.

(Preparation example of color ink composition 1)
The black pigment dispersion (pigment solid content concentration 15% by mass) 15% by mass, the polycarbonate urethane resin particle liquid 1 (solid content concentration 40% by mass) 25% by mass, the polyester urethane resin particle liquid 2 (solid content concentration) 30% by mass) 15% by mass, 1,2-propanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) 15% by mass, 3-methoxy-3-methyl-1-butanol (manufactured by Kuraray Co., Ltd.) 10% by mass, 2,3 -butanediol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 5% by mass, 2-ethylhexyl alcohol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 3% by mass, and polyether-modified surfactant (trade name: Wet270, manufactured by TEGO) 1 mass %, 0.1% by mass of Proxel LV (manufactured by Arch Chemicals Japan Co., Ltd.) as an antibacterial agent, and high-purity water were added to the remaining amount, mixed and stirred, and filtered with a polypropylene filter with an average pore size of 1.0 μm. Color ink composition 1 was prepared by doing so.
The viscosity of the obtained color ink composition 1 was measured using a rotational viscometer (RE-80L, manufactured by Toki Sangyo Co., Ltd.). The measurement conditions were 25° C., a standard cone rotor (1°34′×R24), sample liquid volume of 1.2 mL, rotation speed of 50 rpm, and 3 minutes. The results are shown in Table 1.

(Preparation examples of color ink compositions 2 to 8 and white ink compositions 1 to 4)
Color ink compositions 2 to 8 and white ink compositions 1 to 4 were prepared in the same manner as color ink composition 1, except that the compositions and contents were changed to those shown in Tables 1 to 2. Note that for color ink compositions 5 to 8 and white ink compositions 2 and 4, SAG503A (manufactured by Nissin Chemical Industry Co., Ltd.) was used as a silicone surfactant.
The viscosity was measured in the same manner as for Color Ink Composition 1. The results are shown in Tables 1 and 2.

(Example of preparation of pretreatment liquids 1 to 23)
Polyvalent metal salts, resins, organic solvents, surfactants, antibacterial agents, and water were mixed and stirred according to the formulations (composition and amounts) shown in Tables 3 to 7, and filtered through a polypropylene filter with an average pore size of 1.0 μm. Pretreatment liquids 1 to 23 were prepared by filtration. The pretreatment liquid 6 contains Olfine EXP. as an Olfine-based surfactant. 4300 (manufactured by Nissin Chemical Industry Co., Ltd.) was used.
The viscosity was measured in the same manner as for Color Ink Composition 1. The results are shown in Tables 3-7.

(Examples 1 to 20 and Comparative Examples 1 to 14)
<Image formation>
The obtained ink composition and the obtained pretreatment liquid were filled in an inkjet printer (equipment name: IPSiO GXe5500 modified machine, manufactured by Ricoh Co., Ltd.) in the combinations shown in Tables 8 to 14, and then printed on a PET substrate (HiFi Industrial Film). After printing a halftone image with a resolution of 600 x 600 dpi and a printing rate of 10 to 90% using one drop of pre-treatment liquid (21 pL), the printed matter is passed through a hot air drying unit at 80°C, dried, and fixed. I did it.
Next, ink was printed on the PET substrate on which the pretreatment liquid was printed. After printing a 100% gradation solid color image with a resolution of 600 x 600 dpi using a volume of one ink drop of 21 pL, the printed material was passed through a hot air drying unit at 80° C. to be dried and fixed.

Examples 1 to 20 and Comparative Examples 1 to 14 were evaluated for "color development," "discharge stability (mist)," and "drying properties" as follows. The results are shown in Tables 8-14.

<Evaluation of color development>
The density of the color ink layer of the images created in Examples 1 to 20 and Comparative Examples 1 to 14 was measured using a reflective color spectrophotometric densitometer (X-Rite eXact, manufactured by X-Rite), and the results were evaluated according to the following evaluation criteria. Evaluation was made based on the following. Note that when the concentration of the color ink layer is low, it indicates that the color ink layer sinks into the white ink layer, and when the concentration of the color ink layer is high, the sinking of the color ink layer into the white ink layer is suppressed. Show that there is.
[Evaluation criteria]
A: Concentration is 2.2 or more B: Concentration is 1.8 or more and less than 2.2 C: Concentration is less than 1.8

<Evaluation of number of mist generation (discharge stability) of pre-treatment liquid>
The obtained pretreatment liquid was loaded into an inkjet ejection device (manufactured by Ricoh Co., Ltd.; head: GEN5, manufactured by Ricoh Printing Systems Co., Ltd.), and the ejection status from the 10 nozzles in the center of the head was monitored with a camera (ARTCAM-036MI, (manufactured by Artray Co., Ltd.) for 20 seconds, and the number of mist was evaluated according to the following criteria.
[Evaluation criteria]
A: The number of mist is less than 5 B: The number of mist is 5 or more and less than 10 C: The number of mist is 10 or more

<Evaluation of dryness>
In the above <image formation>, the printed matter was passed through a hot air drying unit at 80°C, and after drying, a filter paper was pressed against the solid part of the solid image, and the transfer of the ink to the filter paper was visually observed, and the following evaluation was performed. Drying properties were evaluated according to standards.
[Evaluation criteria]
A: Transfer to filter paper disappears when drying at 80°C for less than 3 minutes. B: Transfer to filter paper disappears when drying at 80°C for 3 minutes or more but less than 7 minutes. C: Drying at 80°C for 7 minutes or more. , transfer to filter paper is eliminated.

Examples of aspects of the present invention are as follows.
<1> An image forming method in which a treatment liquid, white ink, and color ink are applied to a non-permeable substrate in one scan,
A head that ejects the processing liquid, a head that ejects the white ink, and a head that ejects the color ink exist on the same carriage,
The carriage is arranged parallel to the scanning direction,
The treatment liquid contains a polyvalent metal salt, an organic solvent, and a resin,
The content of the polyvalent metal salt is 0.50% by mass or more and 2.0% by mass or less based on the total amount of the treatment liquid,
The white ink contains a coloring material, an organic solvent, and a resin,
The color ink contains a coloring material, an organic solvent, and a resin,
The image forming method is characterized in that the processing liquid, the white ink, and the color ink have a viscosity at 25° C. of 10 mPa·s or more and 12 mPa·s or less.
<2> The image forming method according to <1>, wherein the polyvalent metal salt is at least either divalent or trivalent.
<3> The image forming method according to any one of <1> to <2>, wherein the resin contained in the processing liquid has a glass transition temperature of 0° C. or higher.
<4> The image forming method according to any one of <1> to <3>, wherein the content of the resin contained in the processing liquid is 4% by mass or more and 15% by mass or less based on the total amount of the processing liquid. It is.

According to the image forming method described in any one of <1> to <4> above, various conventional problems can be solved and the object of the present invention can be achieved.

400 Image forming apparatus 401 Exterior of image forming apparatus 401c Cover of apparatus body 404 Cartridge holder 410 Main tank 410k, 410c, 410m, 410y For each color of black (K), cyan (C), magenta (M), yellow (Y) Main tank 411 Ink storage section 413 Ink discharge port 414 Storage container case 420 Mechanism section 434 Discharge head 436 Supply tube

JP 2019-011528 Publication

Claims (4)

An image forming method in which a processing liquid, a white ink, and a color ink are applied to a non-permeable substrate in one scan, the method comprising:
A head that ejects the processing liquid, a head that ejects the white ink, and a head that ejects the color ink exist on the same carriage,
The carriage is arranged parallel to the scanning direction,
The treatment liquid contains a polyvalent metal salt, an organic solvent, and a resin,
The content of the polyvalent metal salt is 0.50% by mass or more and 2.0% by mass or less based on the total amount of the treatment liquid,
The white ink contains a coloring material, an organic solvent, and a resin,
The color ink contains a coloring material, an organic solvent, and a resin,
An image forming method, wherein the processing liquid, the white ink, and the color ink have a viscosity at 25° C. of 10 mPa·s or more and 12 mPa·s or less. The image forming method according to claim 1, wherein the polyvalent metal salt is at least either divalent or trivalent. The image forming method according to claim 1, wherein the resin contained in the processing liquid has a glass transition temperature of 0° C. or higher. The image forming method according to claim 1, wherein the content of the resin contained in the processing liquid is 4% by mass or more and 15% by mass or less based on the total amount of the processing liquid.